The field of invention relates generally to micro-fabrication of structures. More particularly, the present invention is directed to formation of an etching mask comprising a silicon containing material used in semiconductor processing.
Micro-fabrication involves the fabrication of very small structures, e.g., having features on the order of micro-meters or smaller. One area in which micro-fabrication has had a sizeable impact is in the processing of integrated circuits. As the semiconductor processing industry continues to strive for larger production yields while increasing the circuits per unit area formed on a substrate, micro-fabrication becomes increasingly important. Micro-fabrication provides greater process control while allowing increased reduction of the minimum feature dimension of the structures formed. Other areas of development in which micro-fabrication has been employed include biotechnology, optical technology, mechanical systems and the like.
An exemplary micro-fabrication technique is shown in U.S. Pat. No. 6,334,960 to Willson et al. Willson et al. disclose a method of forming a relief image in a structure. The method includes providing a substrate having a transfer layer. The transfer layer is covered with a polymerizable fluid composition. An imprint device makes mechanical contact with the polymerizable fluid. The imprint device includes a relief structure formed from lands and grooves. The polymerizable fluid composition fills the relief structure, with the thickness of the polymerizable fluid in superimposition with the lands defining a residual thickness. The polymerizable fluid composition is then subjected to conditions to solidify and polymerize the same, forming a solidified polymeric material on the transfer layer that contains a relief structure complimentary to that of the imprint device. The imprint device is then separated from the solid polymeric material such that a replica of the relief structure in the imprint device is formed in the solidified polymeric material. The transfer layer and the solidified polymeric material are subjected to an environment to selectively etch the transfer layer relative to the solidified polymeric material such that a relief image is formed in the transfer layer. Thereafter, conventional etching processes may be employed to transfer the pattern of the relief structure into the substrate.
In recent trends in micro-fabrication of semiconductors, a silicon containing material has been utilized as a masking layer for underlying layers during etching. An example of utilizing silicon as a masking layer is found in, U.S. Pat. No. 6,468,896 to Röhr et al., entitled “Method of Fabricating Semiconductor Components,” discloses a method of depositing a silicon layer upon a metal layer, selectively etching the silicon layer with the selectively etched silicon layer serving as a hard mask when etching of the metal layer occurs.
In another example, U.S. patent application Ser. No. 10/178,947 to Watts et al., entitled “Low Viscosity High Resolution Patterning Material,” discloses a method of forming a conformal layer upon a patterned layer with the conformal layer serving as a hard mask for the patterned layer during etching and the conformal layer being formed from a silicon-containing polymerized fluid.
It is desired, therefore, to provide an improved composition of the silicon-containing material used in imprint lithography processes.